We plan to work on four projects, all related to the nature of malignancy and its possible control: (1) properties of cell cultures of the mouse teratocarcinoma, as a model system in which multipotential cells give rise to differentiated progeny with decreased malignant potential; (2) interaction of concanavalin A with tumor cell surfaces, and isolation of serum components which bind both to cells and to concanavalin A; (3) modification of tumor cell surfaces by the combined use of neuraminidase and emetine to improve on existing methods of producing tumor immunity; (4) biochemical mechanisms involved in the production of interferon, and the relative efficacy of drugs causing the production of interferon.